Step-up switch for electric arc welding



May 22, 1945 H0 VOLT OR 220 VOLT LINE SUPPLIES CURRENT FOR WELDER.

R. E. SMITH 2,376,827

STEP-UP SWITCH FOR ELECTRIC ARC WELDING Filed May 15, 2 Sheets-Sheet lGROUND LEAD TO WORK INVENTOR RUSSELL E. S MITH ATTORNEY May 22, 1945. R.E. SMITH STEP-UP SWITCH FOR ELECTRIC ARC WELDING Filed May 15, 1945 2Sheets-Sheet 2 xmoz o...

on. om. o I 02 ou cow NN NN m R x Y m m W m Mm m :4 s svfi 0B R 0. om om.ov on 00 w\ Patented 22, 1945 Russell E. Smith, lalmer, Mass.

Application May 15, 1943, Serial No. 487,174

4 Claims. (Cl. 315-293) This invention relates to electric arc welding,

and more particularly to an improved apparatus for supplying the weldingarc with an initial high starting current which may be quickly reducedto the normal operating value by means of a manually controlled switchas soon as the work has been heated up sufllclently.

One object of the invention is to provide an arc welding apparatus ofthe above nature in which the circuit through the arc will be manuallycontrolled by means of a solenoid-operated switch actuated by means of apush button switch carried on the electrode handle whereby the highstarting current in the arc will be instantly reduced to normal at thewill of the operator.

A further object is to provide a step-up switch for an electric arcwelding apparatus of the above nature, in which the welding current willbe instantly shifted rapidly from the initially high starting current toa lower normal operating current as soon as the push button is released,without breaking the welding arc.

A further object is to provide an electric arc welding apparatus of theabove nature which will be simple in construction, inexpensive tomanufacture, easy to install and manipulate, compact, and very eflicientand durable in use.

With these and other objects in view there have been illustrated by theaccompanying drawings, two forms in which the invention may convenientlybe embodied in practice.

In the drawings:

Figure 1 represents a diagrammatic view of an electric arc weldingapparatus embodying one form of the invention. v

Figure 2 is a similar diagrammatic view embodylng a second form of theinvention.

The present invention is especially adapted for use in the manufactureof welded fuselage tubing employed in fighting and bombing airplanes.

Referring now to the drawings in which like reference numerals denotecorresponding parts throughout the several views, the letter C indicatesa resistance control box connected by line wires L1 and L2 to a supplyof alternating current. The control box C is connected with a wire G1leading to the work being welded through a ground, and also to a pair oflead plugs l and H for selectively controlling the supply of currentthrough a switch box 2|, to

- be described later, to the arc between the welding electrode E and thework W, at two different values, one for starting and the other fornormal welding. As herein illustrated, these current values may be 80amperes and 60 amperes respectively, and to attain this result the leadplugs wand H are inserted in a Gil-ampere socket l2 and an ail-amperesocket l3 respectively ot thecontrol box C. It will be understood,however, that any other desired "starting" and- "normal welding currentsmay be employed.

In order to provide a manual control to permit shifting the current atwill from the starting to the normal" welding values supplied to thearc, provision is made of a switch having a push button it movablymounted on an electrode handle it, said push button being adapted toform a "bridge connection between a pair' of a stationary switchcontacts Ida and 85b also mounted in said handle it. v

The contact Ida is connected by a wire 16a to a battery I80 which inturn is connected to a wire ltd to one terminal We of a solenoid it, theother terminal it] of said solenoid being joined by a wire lBb to saidcontact I517. The current is conducted through th handle it by asuitable insulated conductor (not shown) which leads to an arm ll of thesolenoid switch through an elongated flexible cable Ho.

The arm I1 is pivoted at i'lb to the switch box 2i, and at Ma to aplunger 18a adapted to reciprocate within the solenoid it. The switchbox 2i is provided with a pair of stationary contacts l8 and i9 adaptedto be connected to the Gil-ampere lead plug it and to the BO-ampere leadplug ll, as by wires 22 and 2201 respectively. The

solenoid arm I1 is normally held in the position shown in Figure l bymeans of a spring 20. It will be understood, however, that when the pushbutton it is pressed inwardly, current will flow through the batterycircuit including the solenoid i6 and will cause the plunger lGa toslide to the right swinging the switch arm l'l away from the contact l8and into engagement with the contact Ill.

By means of this construction it will be seen that the Welding may bestarted with a relatively highcur'rent (such as 80 amperes) and shiftedto a current at lower amperage (such as 60 amperes), whenever theoperator has determined that the work has been sufficiently heated up.It will be understoodthat this shiftover from high to lower amperagewill be made instantly quite rapidly upon release of the push buttonwithout any substantial disturbance to the are passing between theelectrode E and the work W.

Second form of the invention is located in the plunger 23 and serves toprotect the solenoid from the high welding currents passing through theswitch.

A pair of stationary contacts 28 and ill ore provided for connecting thewelding electrode to on tic-ampere lead plug 210; of the control bornfor starting, and a similar pair of contacts lid end 30 are provided forconnecting the welding electrode to the 60-ampere iced plug 1M oi thecontrol box C for nor-moi welding.

As in the that form oi the mventlon, n push button is provided in theelectrode hondle end is adapted to bridge the connection between o pairof stationary contacts ti and it also mounted within said handle. Thecontccts till end it are connected to wires and M, the wire [it lendingdirectly to one tei'rnincll Zita oil the solenoid, while the wise tilllends to battery M, which turn connected by n wire it to the otherterminal Stet oi the solenoid. l'n this'instnnce the solenoid plunger atis biased to the right by coil spring ill which is connected to the beesthe switch boil it. v

The opei'cticn of the second form of in ventlon is clmilor in respectsthnt of the first loom;

While there has been disclosed in this specification two ioinis in whichthe invention may embodied, it to be understood that these forms ehovmfor the purpose of illustration only and thot the invention is not to belimited to the specific disclosures but Hill-,3 be modified and embodiedin various other dorms without depsiting from its spirit. in short, theinvention includes all the modifications end embodiments coming withinthe scope oi the following claims.

Having thus fully described the invention, whet is claimed as is now endfor which it desired secure Letters Potent,

l. In an electrical arc welding apparatus, a resistance control boxhaving at plurellty of leadplunger connected to said em. and a directcurrent circuit for energizing sold solenoid to temw mrily swing saidarm into engagement with the stationary contact connected to the leadplug of higher current value for "ctorting" the weld,

3, In on electricol eve welding opponents, s "resistance control boxhaving it plurality oi sock-'- ets representing diderent welding currentvolues, a, source of current connected to the input tee mimic of saidbox, moons for connecting one output terminal oi said hon i'lu'ongh thegum the ertlcle being welded, the other output nul oi said boatcomprising plucolity oi e sockets representing dlderent welding i315?out sockets representing" different welding current 4 values, means forconnecting sold box to o source of current, a pair of current lend plugsedoptcd to be selectively connected to any two of sold sockets, a switchhaving a. pair of stationery contacts connected to said current leadplugs respectively, said switch having a. movable contact arm forconnection to a welding electrode, spring means to normally hold saidarm in engagement with the stationary contact connected to the lead plugof lower current value, a solenoid-operated plunger connected to saidarm, and a direct current push button-operated circuit for energizingsaid solenoid to temporarily swing said arm into engagement with thestationary contact connected to the lead of higher current value for"starting the weld, said spring serving to automatically return saidswitch arm to its normal position, when said push button is released.

2. In an electrical arc welding apparatus, a resistance control boxhaving a plurality of leadout sockets representing different weldingcurrent values, means for connecting said box to a source of current, apair or current lead plugs adapted to be selectively connected to anytwo of said sockets, a switch having a pair of stationary contactsconnected to said current lead plugs respectively, said switch having amovable contact arm for connection to a welding-electrode, spring meansto normally hold said arm in engagement with the stationary contactconnected to the lead plug oi lower current value, a solenoid-operatedly inserted into ony two oi cold in solo noid opemted switch llnvlngpoll: of ototion my contuctc connected to cold current lent "allrespectively, sold switch. comprising; o stotionnry contests in circuitwith the can-tens iced plug for starting, ceccn of stntionnry contactscircuit with tl current lend plugior novmel welding, o rod carrying itswitch cross our, in com meetingsaid :rod to the plunger of cold spyingfor normally holding out in content with the lower current wot-1Lcontacts, to push button-operated d circuit to energize cold solenoidplunger to move sold it into enga p i higher current conic-lets oi sci-dowl i'cepcnslve to cold for on switch but to nutomctlcolly veturn highercurrent contacts to lower Cull. repldly when sold push button is wherebythe weldingmoy be started 'wl 1 ":16 normal current of lower ompercgel'or the vemolnder of said welding operation t. In on electrical arcwelding apparatus, u reslstnnce control box liovim o plurality oisockets representing diflei'ent welding current voluec, t. source ofcurrent connected to the input terminals oi said box, means forconnecting one output terminal of said box to the article being welded,the other output terminal of said box comprising c. plurality oflead-out sockets representing dihierent welding current values, s. pairor current lend plugs to be selectively inserted into any two of saidsockets, n. solenoid-operated switch having a. pair of stationarycontacts connected to said current lend plugs respectively, said switchcomprising c. pair of stationary contacts in circuit with the highercurrent lead plug for starting,

7 e second pair of stationary contacts in circuit with the lower currentlead plug ior normal welding, a slidable rod carrying a. switch crossbar, means for connecting said rod to th plunger of said solenoid,spring means for normally holding said movable bar in contact with thelower current stationary contacts, and a push buttonoperated directcurrent circuit to energize said solenoid and cause said plunger to movesaid bar into engagement with the higher current contacts of saidswitch, whereby the welding may be started with a relatively highamperage until the work has been warmed up sufflciently, and may becontinued at the normal current or lower smperage for the remainder ofsaid welding operation.

RUSSELL E. SMITH.

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